Screen Resolution: add space for 4-digit values

Add logic that composes screen resolution string with non-breaking
spaces. Now setting page will show "1 080 x 1 280" instead of "1080 x
1280"

Test: atest -c <SETTINGS_APP_PATH>/tests/unit/src/com/android/settings/display/ScreenResolutionFragmentTest.java
Test: verified on device
Flag: EXEMPT no API change
Bug: 385895191
Change-Id: I9a4bbd7c20e8c700dee6e997a36d4fda69f4d780
diff --git a/src/com/android/settings/display/ScreenResolutionFragment.java b/src/com/android/settings/display/ScreenResolutionFragment.java
index 224a6f3..9f6ae17 100644
--- a/src/com/android/settings/display/ScreenResolutionFragment.java
+++ b/src/com/android/settings/display/ScreenResolutionFragment.java
@@ -28,6 +28,7 @@
 import android.util.Log;
 import android.view.Display;
 
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.VisibleForTesting;
 import androidx.preference.PreferenceScreen;
@@ -52,11 +53,15 @@
 /** Preference fragment used for switch screen resolution */
 @SearchIndexable
 public class ScreenResolutionFragment extends RadioButtonPickerFragment {
+    public static final String NON_BREAKING_SPACE = "\u00A0";
+
     private static final String TAG = "ScreenResolution";
 
     private Resources mResources;
     private static final String SCREEN_RESOLUTION = "user_selected_resolution";
     private static final String SCREEN_RESOLUTION_KEY = "screen_resolution";
+    private static final int RESOLUTION_SPACE_THRESHOLD = 1_000;
+    private static final int RESOLUTION_SPACE_THRESHOLD_DIGIT_AMOUNT = 3;
     private Display mDefaultDisplay;
     private String[] mScreenResolutionOptions;
     private Set<Point> mResolutions;
@@ -94,12 +99,45 @@
 
 
     private SpannableString getResolutionSpannable(int width, int height) {
-        String resolutionString = width + " x " + height;
+        String resolutionString = getResolutionString(width, height);
         String accessibleText = mResources.getString(
                 R.string.screen_resolution_delimiter_a11y, width, height);
         return Utils.createAccessibleSequence(resolutionString, accessibleText);
     }
 
+    /**
+     * Formats the given width and height into a resolution string, inserting non-breaking
+     * spaces as thousand separators if the values exceed a specified threshold.
+     *
+     * @param width  The width value.
+     * @param height The height value.
+     * @return A formatted string representing the resolution (e.g., "1 080 x 1 280").
+     * Non-breaking spaces are used to ensure the numbers and 'x' stay together.
+     * If the width or height is less than RESOLUTION_SPACE_THRESHOLD, no spaces are added.
+     */
+    @NonNull
+    @VisibleForTesting
+    static String getResolutionString(int width, int height) {
+        StringBuilder resolutionStrBldr = new StringBuilder(String.valueOf(width));
+        if (width >= RESOLUTION_SPACE_THRESHOLD) {
+            int insertWidthPosition =
+                    resolutionStrBldr.length() - RESOLUTION_SPACE_THRESHOLD_DIGIT_AMOUNT;
+            resolutionStrBldr.insert(insertWidthPosition, NON_BREAKING_SPACE);
+        }
+        resolutionStrBldr.append(NON_BREAKING_SPACE);
+        resolutionStrBldr.append("x");
+        resolutionStrBldr.append(NON_BREAKING_SPACE);
+
+        resolutionStrBldr.append(String.valueOf(height));
+        if (height >= RESOLUTION_SPACE_THRESHOLD) {
+            int insertHeightPosition =
+                    resolutionStrBldr.length() - RESOLUTION_SPACE_THRESHOLD_DIGIT_AMOUNT;
+            resolutionStrBldr.insert(insertHeightPosition, NON_BREAKING_SPACE);
+        }
+
+        return resolutionStrBldr.toString();
+    }
+
     @Override
     protected int getPreferenceScreenResId() {
         return R.xml.screen_resolution_settings;
diff --git a/tests/unit/src/com/android/settings/display/ScreenResolutionFragmentTest.java b/tests/unit/src/com/android/settings/display/ScreenResolutionFragmentTest.java
index 8409531..8a8a681 100644
--- a/tests/unit/src/com/android/settings/display/ScreenResolutionFragmentTest.java
+++ b/tests/unit/src/com/android/settings/display/ScreenResolutionFragmentTest.java
@@ -110,4 +110,28 @@
 
         assertThat(preference.getSummary().toString().contentEquals(summary)).isTrue();
     }
+
+    @Test
+    public void testResolutionString_widthAndHeightAboveThreshold() {
+        String result = ScreenResolutionFragment.getResolutionString(1080, 1280);
+        assertThat(result).isEqualTo("1\u00A0080\u00A0x\u00A01\u00A0280");
+    }
+
+    @Test
+    public void testResolutionString_widthAboveThreshold_heightBelowThreshold() {
+        String result = ScreenResolutionFragment.getResolutionString(1080, 980);
+        assertThat(result).isEqualTo("1\u00A0080\u00A0x\u00A0980");
+    }
+
+    @Test
+    public void testResolutionString_widthBelowThreshold_heightBelowThreshold() {
+        String result = ScreenResolutionFragment.getResolutionString(980, 980);
+        assertThat(result).isEqualTo("980\u00A0x\u00A0980");
+    }
+
+    @Test
+    public void testResolutionString_widthBelowThreshold_heightAboveThreshold() {
+        String result = ScreenResolutionFragment.getResolutionString(980, 1080);
+        assertThat(result).isEqualTo("980\u00A0x\u00A01\u00A0080");
+    }
 }